This invention relates to switch assemblies for use with large dynamoelectric machines including electric motors and generators having a control switch such as an overload reset switch mounted on the motor shell or endshield of the machine, and more particularly, to an improved, lower cost assembly.
It is not uncommon to mount larger dynamoelectric machines such as higher fractional horsepower or multi-horsepower motors or generators to a floor or other fixture at a using site. For this purpose, a bracket is attached to the motor with the bracket then being mounted to the floor or fixture. It is also not uncommon for the motor or generator to have an associated switch mounted to its outer shell or endshield. The switch is typically an overload protector type switch which interrupts power flow to the machine when an overload condition occurs. The switch is then either manually reset when the overload condition has been corrected; or, in some systems, the switch can be automatically reset. Electrical conduit for conveying power to the machine is routed from a central, power distribution network to a conduit box or enclosure in which the switch is also mounted. When electrically connected, the switch is interposed in the circuit path for powering the machine.
Previously, the switch was attached to a mounting bracket which was then riveted or welded to inside walls of the conduit box. This installation thus required a secondary manufacturing step which added cost to the machine assembly and its installation. Further, were the switch to fail, replacement of the switch required the replacement of the conduit box with the associated disconnection and reconnection of the conduits. This imposed an additional cost to the maintenance of the system in which the machine is used. Finally, there were a number of different sized conduit boxes which were used with different machines. By standardizing the size of a switch mounting bracket, it would be possible to reduce the number of boxes required and therefore reduce inventory costs.